There are overlapping claims as to who ought to get the credit; apparently, it was an idea whose time had come. In 1856, Sir William Herschel-an English magistrate in India-began requiring fingerprints on contracts, but it's not clear that he ever used them to identify criminals. In 1880, Dr. Henry Faulds of Scotland published a paper on the use of fingerprints for identification, but he was unable to interest law enforcement in the idea. In 1883, Mark Twain's Life on the Mississippi included the identification of a murderer using a fingerprint. (He would use the same trick again in his 1894 novel, Pudd'nhead Wilson.)

Starting in 1888, Sir Francis Galton began publishing works about fingerprints, identifying patterns, creating a system of classification, and determining that the odds of two people having the same fingerprint were vanishingly small, thus making them suitable for forensic work. The first to actually use his system to convict a criminal was Argentine police officer Juan Vucetich, in 1892. The Henry classification system, devised by Sir Edward Richard Henry in 1896-7, enabled prints to be classified and sorted; it was adopted by Scotland Yard in 1901, and became the ubiquitous method of classifying fingerprints from then until the computer age.

To learn more about the future of positive identification, follow this link to information about DNA fingerprinting.